<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Scroll Two Div Parallel</title>
    <style>
        .LeftDiv,
        .RightDiv {
            width: calc(50% - 80px);
            margin: 10px;
            min-width: 80px;
            display: inline-block;
            padding: 20px;
            max-height: 100px;
            overflow-y: scroll;
        }

        .LeftDiv {
            background: #eee;
        }

        .RightDiv {
            background: #faebd7;
        }

        .LeftDiv div,
        .RightDiv div {
            padding: 12px;
            font-size: 16px;
            margin: 4px;
            border: 1px solid #bbb;
        }
    </style>
</head>

<body>
    <div id="LeftDiv" class="LeftDiv" onscroll="parallelScrollRightDiv(this)">
        LEFT DIV
        <div>Table 2 - Row1</div>
        <div>Table 2 - Row2</div>
        <div>Table 2 - Row3</div>
        <div>Table 2 - Row4</div>
        <div>Table 2 - Row5</div>
        <div>Table 2 - Row6</div>
        <div>Table 2 - Row7</div>
        <div>Table 2 - Row8</div>
        <div>Table 2 - Row9</div>
        <div>Table 2 - Row10</div>
    </div>

    <div id="RightDiv" class="RightDiv" onscroll="parallelScrollLeftDiv()">
        RIGHT DIV
        <div>Table 1 - Row1</div>
        <div>Table 1 - Row2</div>
        <div>Table 1 - Row3</div>
        <div>Table 1 - Row4</div>
        <div>Table 1 - Row5</div>
        <div>Table 1 - Row6</div>
        <div>Table 1 - Row8</div>
    </div>
    <script>

        function parallelScrollLeftDiv() {
            document.getElementById('LeftDiv').scrollTop = document.getElementById('RightDiv').scrollTop;
        }


        function parallelScrollRightDiv(elem) {
            document.getElementById('RightDiv').scrollTop = elem.scrollTop;
            document.getElementById('RightDiv').scrollLeft = elem.scrollLeft;
        }

    </script>
</body>

</html>